公开(公告)号：US11041722B2

公开(公告)日：2021-06-22

申请号：US16042742

申请日：2018-07-23

Applicant: Analog Devices, Inc.

Inventor： Jiefeng Yan ,  William A. Clark ,  Ronald A. Kapusta, Jr.

IPC: G01C19/5726 ,  G01C19/5755

Abstract: Systems and methods for sensing angular motion using a microelectromechanical system (MEMS) gyroscope are described. These systems and methods may be useful for sensing angular motion in the presence of low-frequency noise, which may be noise below 1 KHz. In a system for sensing angular motion, low-frequency noise may give rise to duty cycle jitter, which may affect the demodulation of the sense signal and cause errors in angular motion estimates. The systems and methods described herein address this problem by relying on double-edge phase detection technique that involves sensing when the rising and falling edges of the resonator signal deviate from their expected values in the idealized 50% duty cycle scenario. To prevent the formation of ripples in the double-edge phase detection that may otherwise affect the demodulation of the sense signal, a switch may be used. The switch may be maintained in a non-conductive state when a ripple is received.

公开(公告)号：US10852136B2

公开(公告)日：2020-12-01

申请号：US15690504

申请日：2017-08-30

Applicant: Analog Devices, Inc.

Inventor： Jiefeng Yan ,  Ronald A. Kapusta, Jr. ,  Jianrong Chen

IPC: G01R23/14 ,  G01C19/5726 ,  G01C19/5755

Abstract: A method for detecting frequency mismatch in microelectromechanical systems (MEMS) gyroscopes is described. Detection of the frequency mismatch between a drive signal and a sense signal may be performed by generating an output signal whose spectrum reflects the physical characteristics of the gyroscope, and using the output signal to determine the frequency fC of the sense signal. The output signal may be generated by cross-correlating a random or pseudo-random noise signal with a response signal, where the response signal can be obtained by allowing the noise signal to pass through a system designed to have a noise transfer function that mimics the frequency response of the gyroscope. Since the noise signal is random or pseudo-random, cross-correlating the noise signal with the response signal reveals spectral characteristics of the gyroscope. To improve computational efficiency, the cross-correlation can be performed on demodulated versions of the noise signal and the response signal.

公开(公告)号：US10578435B2

公开(公告)日：2020-03-03

申请号：US15869163

申请日：2018-01-12

Applicant: Analog Devices, Inc.

Inventor： James Lin ,  Ronald A. Kapusta, Jr. ,  Lijun Gao

IPC: G01C19/56 ,  B81B3/00

Abstract: Circuits and methods for compensating microelectromechanical system (MEMS) gyroscopes for quality factor variations are described. Quality factor variations arise when mechanical losses are introduced in the gyroscope's resonator, for example due to thermoelastic damping or squeeze-film damping, which may hinder the gyroscope's ability to accurately sense angular velocity. Quality factor compensation may be performed by generating a compensation signal having a time decay rate that depends on the quality factor of resonator. In this way, artifacts that may otherwise arise in gyroscope's output are limited. Additionally, or alternatively, quality factor compensation may be performed by controlling the force with which the gyroscope's resonator is driven. This may be achieved, for example, by controlling the average value of the drive signal.

公开(公告)号：US10247600B2

公开(公告)日：2019-04-02

申请号：US15348521

申请日：2016-11-10

Applicant: Analog Devices, Inc.

Inventor： Youn-Jae Kook ,  Jose Barreiro Silva ,  Jianrong Chen ,  Ronald A. Kapusta, Jr.

IPC: G01C19/5776 ,  G01C19/5726 ,  G01H13/00 ,  G01P15/00 ,  G01P21/00

Abstract: Systems and techniques are described for matching the resonance frequencies of multiple resonators. In some embodiments, a resonator generates an output signal reflecting the resonator's response to an input drive signal and an input noise signal. The output signal is then compared to the noise signal to derive a signal representative of the resonance frequency of the resonator. Comparing that signal to the output signal of a second resonator gives an indication of whether there is a difference between the resonance frequencies of the two resonators. If there is, one or both of the resonators may be adjusted. In this manner, the resonance frequencies of resonators may be matched during normal operation of the resonators.